It is a bit difficult to understand you first question.
what would be wrong if she becomes muslim? or do you mean something else?
regards to following shaykhs that are upon the Salafs way.
The most commonly know in our time is.
shaykh Muhammad bin Uthaymeen shaykh Nasir ud deen al albani shaykh ul islam ibn Taymiyyah shaykh Muhammad bin abd al wahhab shaykh rabee al madhkhali shaykh ibn baz
And many more!
read more from the different topics in the subjects board and it will be more clear in sha Allah( God willing)